[Lindzorz]

I use the Martha Stewart one from Petsmart. It's a fairly thick brown rubber mat that has high lips around the sides. It is only a mat, the pad isn't secured, but I haven't had any problems whatsoever with leaks through it. I believe it may have been $19.99. The line is only sold in Petsmarts, and the box is long and slender because the holder is wrapped up inside. Took me a while to figure out where it was because of the box size/shape.

Hope that helps! Good luck!